1. Field of the Invention
The present invention relates to a semiconductor package, more particularly, to a semiconductor package wherein each length from an electrode of a semiconductor element to a terminal for external connection is made equal to one another and the terminal for external connection is extended only from one side of a package, and a semiconductor module using the semiconductor package.
2. Discussion of Background
FIG. 11 is a perspective view showing an outer appearance of the conventional semiconductor package, for example, of a SVP (surface vertical package) proposed and used in a DRAM operating at a high speed, and FIG. 12 is a plan view showing the inside thereof. In the drawings, numeral 1 denotes a semiconductor package, numeral 2 a lead for external connection, numeral 3 a semiconductor element, numeral 4 an electrode, numeral 5 a wire, and numeral 6 a die pad, respectively. In the present package, the lead 2 for external connection is placed only at one side of the semiconductor package 1. In the inside of the package, electrodes 4 are arranged in approximately one row along one side of the semiconductor element 3. The lead 2 for external connection is electrically connected with the electrode 4 through the wire 5. Electrodes 4 are arranged in approximately one row, and the leads 2 for external connection are arranged only at the side nearest to the electrode 4 of the semiconductor package 1, so that each length of the electrical wiring is short in any electrode 4 and is approximately equal to one another.
A semiconductor package wherein a lead for external connection is arranged only at one side of a semiconductor package is proposed also in Japanese Unexamined Patent Publications No. 61289/1994, No. 21684/1993, No. 321441/1995 or the like. In Japanese Unexamined Patent Publication No. 61289/1994, leads for external connection are arranged at the short side of a semiconductor package, and a vertical packaging operation is conducted with respect to a substrate for packaging so as to reduce the packaging area. In Japanese Unexamined Patent Publication No. 21684/1993, a module is proposed wherein a tape with a lead is extended externally from only one side of a package and is bent into a L-shape so as to package the package to a print substrate. Further, in Japanese Unexmined Patent Publication No. 321441/1995, a semiconductor package is proposed wherein a flexible lead extended from one direction of the semiconductor package is bent into an optional angle, so as to make it possible to package it vertically or obliquely with respect to a wiring substrate with sufficiently securing the contact area with the electrode of the wiring electrode.
In recent years, the reduction of packaging height of the conventional semiconductor package is desired due to requirements for smaller parts size, packaging area and volume with the increase of portable electronic devices. FIG. 13 is a side view showing a case where the conventional semiconductor package 1 shown in FIGS. 11 and 12 is packaged. In the drawing, numeral 7 denotes a substrate for packaging, and H denotes a packaging height. The conventional semiconductor package 1 of an aforementioned configuration is packaged vertically with respect to the substrate 7 for packaging, so that the packaging height H of the package is increased. Also in semiconductor modules proposed in Japanese Unexamined Patent Publications No. 61289/1994 and No. 21684/1993, a semiconductor package is likewise packaged vertically with respect to the substrate for packaging, thereby causing a problem of a large packaging height H. In a semiconductor module disclosed in Japanese Unexamined Patent Publication No. 321441/1995, there is proposed a method for packaging a semiconductor package in an oblique direction with respect to a wiring substrate, but the method causes a problem that the number of parts increases because a holding member for supporting a semiconductor package is required.
When a plurality of semiconductor packages are piled up and packaged for reducing the packaging volume of the semiconductor package, there has been a problem that the heat generation at a high speed operation increases and a temperature increases excessively, thus making the practical use thereof difficult.
The present invention is made to solve the aforementioned problems, and an object of the present invention is, in a semiconductor package and a semiconductor module with a plurality of semiconductor packages mounted thereon, to obtain a semiconductor package and a semiconductor module using it capable of reducing the packaging height with respect to a substrate for packaging, thus making it possible to obtain smaller parts size, and reduced packaging area and volume.